Experimental investigation on regulated and unregulated emissions of a diesel engine fueled with ultra-low sulfur diesel fuel blended with biodiesel from waste cooking oil

Experiments were conducted on a 4-cylinder direct-injection diesel engine using ultra-low sulfur diesel, bi oesel and their blends, to investigate the regulated and unregulated emissions of the engine under five engine loads at an engine speed of 1800 rev/min. Blended fuels containing 19.6%, 39.4%, 59.4% and 79.6% by volume of biodiesel, corresponding to 2%, 4%, 6% and 8% by mass of oxygen in the blended fuel, were used. Biodiesel used in this study was converted from waste cooking oil.The following results are obtained with an increase of biodiesel in the fuel. The brake specific fuel consumption and the brake thermal efficiency increase. The HC and CO emissions decrease while NO_x and NO₂ emissions increase. The smoke opacity and particulate mass concentrations reduce significantly at high engine load. In addition, for submicron particles, the geometry mean diameter of the particles becomes smaller while the total number concentration increases. For the unregulated gaseous emissions, generally, the emissions of formaldehyde, 1,3-butadiene, toluene, xylene decrease, however, acetaldehyde and benzene emissions increase.The results indicate that the combination of ultra-low sulfur diesel and biodiesel from waste cooking oil gives similar results to those in the literature using higher sulfur diesel fuels and biodiesel from other sources.     

Combustion characteristics of the direct injection diesel engine fuelled with corn oil methyl ester

Petroleum-based fuels is a finite resource that is rapidly depleting. Consequently, petroleum reserves are not sufficient enough to last many years. In this research, an experimental investigation has been performed to give insight into the potential of biodiesel as an alternative fuel for direct injection (DI) diesel engines. The experimental work has been carried out to estimate the combustion characteristics of a single-cylinder, four-stroke, DI diesel engine fuelled with corn oil methyl ester (COME) and diesel blends. The COME was preheated to temperatures namely 50°C, 70°C and 90°C before it was supplied to the engine. The optimised preheated temperature of 70°C was chosen based on the higher brake thermal efficiency and lower specific fuel consumption. The performance, emission and combustion characteristics are evaluated by running the engine with COME and diesel blends at this preheated temperature. In this paper, the combustion characteristics are only discussed. The combustion characteristics such as ignition delay, maximum rate of pressure, heat release rate, cumulative heat release rate, mass fraction burned and combustion duration of COME methyl ester and diesel were evaluated and compared with neat diesel. The rate of pressure rise and maximum combustion pressure inside the cylinder were high for COME blends compared with neat diesel. The heat release rate of diesel is higher compared with COME blends. The ignition delay and combustion duration are decreased for COME blends compared with neat diesel. The cumulative heat release rate and mass fraction burnt of COME blends are higher than neat diesel.     

Study on the outcome of a cetane improver on the emission characteristics of a diesel engine

ABSTRACT

Dimethyl carbonate (DMC), a cetane improver, is used as a fuel additive to investigate the exhaust emission in diesel engine. Neem oil biodiesel (B100), neem oil biodiesel + dimethyl carbonate (B100+DMC) and diesel were used as test fuels. DMC is added 0.5% by volume to biodiesel. This research work was executed in a four-stroke, single-cylinder diesel engine. Owing to the percentage of DMC in biodiesel, carbon monoxide (CO) and hydrocarbon (HC) emissions were dropped corresponding to diesel. A considerable amount of nitrogen oxide (NO_x) is decreased when diesel is used, and by the addition of B100+DMC, NO_x were slightly reduced compared to B100.     

Performance and emissions analysis of a diesel engine directly fuelled with waste cooking oil biodiesel

This research focuses on a comparative study of the physical and chemical properties of waste cooking oil (WCO) biodiesel with China stage IV diesel fuel. The estimate method of excess air ratio and the heating value ratio of an engine's cylinder mixture are proposed based on the differences of properties of two fuels. The bench tests of engine performance are carried out with an engine fuelled with two fuels separately. The estimated excess air ratio and the heating value ratio of an engine's cylinder mixture through the method are approximate to the experiment results. This comparison demonstrates that the estimate method can be applied to the performance analysis of an engine. Compared with China stage IV diesel, when a diesel engine is fuelled with WCO biodiesel, the torque and power decline from 1.9% to 13.8%; the brake-speci?c fuel consumption rises from 3.7% to 15.6%; CO, HC and PM emissions decrease significantly and NO_X emissions increase slightly.     

Experimental investigations on the influence of properties of Calophyllum inophyllum biodiesel on performance,combustion, and emission characteristics of a DI diesel engine

The current state of future energy and environmental crises has revitalised the need to find alternative sources of energy due to escalating oil prices and depleting oil reserves. To meet increasing energy requirements, there has been a growing interest in alternative fuels like biodiesel that can become a suitable diesel fuel substitute for compression ignition engine. Biodiesel offers a very promising alternative to diesel fuel, since they are renewable and have similar properties. Calophyllum inophyllum seed oil collected from different restaurants in the Nagapattinam region of South India was converted into methyl esters (biodiesel) by transesterification. Biodiesel produced from C. inophyllum oil was blended with diesel by different volume proportions (25%, 50%, and 75%). Biodiesel and its blends were tested on a direct injection (DI) diesel engine at a constant speed by varying loads from 0% to 100% in steps of 20% to analyse its performance, emission, and combustion characteristics. The results obtained were compared with that of diesel fuel. B25 (27.5%) showed better performance than diesel fuel (26.28%) at full load and B50 showed performances similar to diesel fuel. Smoke density of B25 was slightly (2.6%) higher than that of diesel at full load conditions. At full load, measured carbon monoxide emissions for B25 and B50 were 4% lower than that of diesel. Hydrocarbon emissions for B25 and B100 were 5.37% and 25.8% higher than that of diesel, respectively. Nitrogen oxides (NO_x) emission was lower for all biodiesel blends. NO_x emissions of B100 and B75 were lower than that of diesel by 22.16% and 13.29% at full load, respectively. Combustion profile was smoother, and no knocking problem was observed while operating with biodiesel blends. B75 produced peak cylinder pressure.     

Bio-ethanol additive effect on direct injection diesel engine performance,emission and combustion characteristics – an experimental examination

ABSTRACT

The present investigation explores the effect of dairy scum oil methyl ester (DSOME) blends and ethanol additive on TV1 Kirloskar diesel engine performance, combustion and emission characteristics. From the experimental study, it is concluded that DSOME-B20 (20% dairy scum biodiesel?+?80% diesel) has shown appreciable performance and lower HC and CO emissions among all other blends. Hence DSOME-B20 is optimised as best fuel blend and it is carried for further investigations to study the effect of bio-ethanol additive on diesel engine performance. From the study it apparent that diesel engine operated with ethanol additive and 20% dairy scum biodiesel blended fuels shown the satisfactorily improved emission characteristics when compared to petroleum diesel fuel operation. Finally, from the experimental investigation, it concludes that addition of ethanol shown the slightly higher HC, CO emission and improved BTE, BSFC, NOx and CO₂ than sole B20 biodiesel blend. Among all three (3%, 6% and 9%) ethanol additive ratios, E6% (6%-ethanol with B20) ethanol additive exhibits slightly better BTE, BSFC, cylinder pressure and heat release rate hence 6% ethanol additive with B20 biodiesel blend would furnish beneficial effects in the diesel engine.     

Experimental analysis of Deccan hemp oil as a new energy feedstock for compression ignition engine

This study investigates the biodiesel from Deccan hemp oil and its blends for the purpose of fuelling diesel engine. The performance and emission characteristics of Deccan hemp biodiesel are estimated and compared with diesel fuel. The experimental investigations are carried out with different blends of Deccan hemp biodiesel. Results show that brake thermal efficiency is improved significantly by 4.15% with 50 BDH when compared with diesel fuel. The Deccan hemp biodiesel reduces NO_x, HC and CO emission along with a marginal increase in CO₂ and smoke emissions with an increase in the biodiesel proportion in the diesel fuel. The improvement in heat release rates shows an increase in the combustion rate with different percentage blends of Deccan hemp biodiesel. From the engine test results, it has been established that 30–50 BDH of Deccan hemp biodiesel can be substituted for diesel.     

Emissions characteristics of a diesel engine operating on biodiesel and biodiesel blended with ethanol and methanol

Euro V diesel fuel, pure biodiesel and biodiesel blended with 5%, 10% and 15% of ethanol or methanol were tested on a 4-cylinder naturally-aspirated direct-injection diesel engine. Experiments were conducted under five engine loads at a steady speed of 1800 r/min. The study aims to investigate the effects of the blended fuels on reducing NO_x and particulate. On the whole, compared with Euro V diesel fuel, the blended fuels could lead to reduction of both NO_x and PM of a diesel engine, with the biodiesel-methanol blends being more effective than the biodiesel-ethanol blends. The effectiveness of NO_x and particulate reductions is more effective with increase of alcohol in the blends. With high percentage of alcohol in the blends, the HC, CO emissions could increase and the brake thermal efficiency might be slightly reduced but the use of 5% blends could reduce the HC and CO emissions as well. With the diesel oxidation catalyst (DOC), the HC, CO and particulate emissions can be further reduced.     

Performance and emission characteristics of cashew nut shell oil on the CI engine

This article is an effort to address the need for a non-cooking oil-based biodiesel. Here, the experimental work is done on a single cylinder, direct injection CI engine using cashew nut shell oil biodiesel blends under constant speed. The cashew nut shell liquid (CNSL) biodiesel is blended with the diesel fuel and used as biodiesel blend. Blends used for testing are B20, B40 and B60. The effect of the fuels on engine power, brake thermal efficiency (BTE) and exhaust gas temperature was determined by performance tests. The influences of blends on CO, CO₂, HC and NO_x emissions were investigated by emission tests. The BTE values of biodiesel are closer to diesel. Compared to diesel, all the biodiesel blends gave lesser unburnt hydrocarbon (HC), carbon monoxide (CO) and smoke emissions. Slightly higher NO_x emissions were found in CNSL biodiesel blends, which is typical of the other biodiesels.     

Experimental study on particulate and NOx emissions of a diesel engine fueled with ultra low sulfur diesel, RME-diesel blends and PME-diesel blends

Ultra low sulfur diesel and two different kinds of biodiesel fuels blended with baseline diesel fuel in 5% and 20% v/v were tested in a Cummins 4BTA direct injection diesel engine, with a turbocharger and an intercooler. Experiments were conducted under five engine loads at two steady speeds (1500 rpm and 2500 rpm). The study aims at investigating the engine performance, NO_x emission, smoke opacity, PM composition, PM size distribution and comparing the impacts of low sulfur content of biodiesel with ULSD on the particulate emission. The results indicate that, compared to base diesel fuel, the increase of biodiesel in blends could cause certain increase in both brake specific fuel consumption and brake thermal efficiency. Compared with baseline diesel fuel, the biodiesel blends bring about more NO_x emissions. With the proportion of biodiesel increase in blends, the smoke opacity decreases, while total particle number concentration increases. Meanwhile the ULSD gives lower NO_x emissions, smoke opacity and total number concentration than those of baseline diesel fuel. In addition, the percentages of SOF and sulfate in particulates increase with biodiesel in blends, while the dry soot friction decreases obviously. Compared with baseline diesel fuel, the biodiesel blends increase the total nucleation number concentration, while ULSD reduces the total nucleation number concentration effectively, although they all have lower sulfur content. It means that, for ULSD, the lower sulfur content is the dominant factor for suppressing nucleation particles formation, while for biodiesel blends, lower volatile, lower aromatic content and higher oxygen content of biodiesel are key factors for improving the nucleation particles formation. The results demonstrate that the higher NO_x emission and total nucleation number concentration are considered as the big obstacles of the application of biodiesel in diesel engine.     

Performance analysis of low heat rejection diesel engine,using Mahua oil bio fuel

In the present investigation, the effect of thermal barrier coated piston on the performance and emission characteristics of mahua-biodiesel-fuelled diesel engine was studied and compared with those of neat diesel fuel. The piston, cylinder walls and the valves of the engine were coated with 0.25?mm thickness of Al₂O₃ material without affecting the compression ratio of the engine. Experiments were conducted using diesel and biodiesel blend (B20) in the engine with and without coating. The results revealed that specific fuel consumption was decreased by 8.5% and the brake thermal efficiency was increased by 6.2% for biodiesel blend with coated engine compared with the base engine with neat diesel fuel. The exhaust emissions CO, NO_x and HC emissions were also decreased for biodiesel blend with coated engine compared with base engine.     

Experimental investigation of engine emissions with marine gas oil-oxygenate blends

This paper investigates the diesel engine performance and exhaust emissions with marine gas oil-alternative fuel additive. Marine gas oil (MGO) was selected as base fuel for the engine experiments. An oxygenate, diethylene glycol dimethyl ether (DGM), and a biodiesel (BD) jatropha oil methyl ester (JOME) with a volume of 10% were blended with the MGO fuel. JOME was derived from inedible jatropha oil. Lower emissions with diesel-BD blends (soybean methyl ester, rapeseed methyl ester etc.) have been established so far, but the effect of MGO-BD (JOME) blends on engine performance and emissions has been a growing interest as JOME (BD) is derived from inedible oil and MGO is frequently used in maritime transports. No phase separation between MGO-DGM and MGO-JOME blends was found. The neat MGO, MGO-DGM and MGO-JOME blends are termed as MGO, Ox10 and B10 respectively. The experiments were conducted with a six-cylinder, four-stroke, turbocharged, direct-injection Scania DC 1102 (DI) diesel engine. The experimental results showed significant reductions in fine particle number and mass emissions, PM and smoke emissions with Ox10 and B10 fuels compared to the MGO fuel. Other emissions including total unburned hydrocarbon (THC), carbon monoxide (CO) and engine noise were also reduced with the Ox10 and B10 fuels, while maintaining similar brake specific fuel consumption (BSFC) and thermal efficiency with MGO fuel. Oxides of nitrogen (NOx) emissions, on the other hand, were slightly higher with the Ox10 and B10 fuels at high engine load conditions.     

Emission characteristics of neat rapeseed oil fuel in diesel engine

Studies show that the combustion of fossil fuel is the main cause of increasing global atmospheric carbon dioxide (CO₂) levels, which is the cause of the greenhouse effect. This has promoted increased research world-wide in a bid to source a greener alternative fuel substitute for conventional fossil fuel. Biofuel appears to be an alternative energy source for diesel engines. Although the combustion of biofuels produces CO₂, the same quantity is absorbed by plants during photosynthesis, hence CO₂ levels are kept in balance. The sulphur content of plant fuels is also low and less than 0.01% by weight compared to 0.05% by weight for diesel fuel. The effect of acid rain is therefore reduced or ameliorated. High viscosity is one of the major problems relating to the direct use of neat vegetable oils as fuels. One method of reducing viscosity is by blending with a low viscosity and volatile fuel. This paper investigates the emission characteristics of neat rapeseed oil and its blend with diesel fuel in a single cylinder unmodified diesel engine. Tests were also conducted on pure diesel fuel so that a comparative assessment could be made. Test results showed reduced hydrocarbon (HC) emissions when running on biofuels. The CO production was higher when running on biofuel at high engine speed and was significantly reduced at low speed operations. The CO₂ emissions were similar for all fuels. The analyses of lubrication oil after the runs on plant fuels showed a net reduction in viscosity.     

Evaporation rate and engine performance analysis of coated diesel engine using Raphanus sativus biodiesel and its diesel blends

An experimental investigation to measure the evaporation rates, PSZ-coated engine performance and emissions of radish biodiesel (Methyl Ester of radish oil) and its blends in different volumetric proportions with diesel is presented. The thermo-physical properties of all the fuel blends have been measured and presented. Evaporation rates of neat radish biodiesel, neat diesel and their bends have been measured under slow convective environment of air velocity of 0.2?m/s with a constant temperature of 200°C. Evaporation constants have been determined by using the droplet regression rate data. The neat fuels and fuel blends have been utilised in a test engine with different load conditions to evaluate the performance and emission characteristics of the fuels. From the observed evaporation, performance and emissions characteristics, it can be suggested that a blend of B25–B75 could be optimally used in coated diesel engine settings without any modifications on it.     

Performance characteristics of palm kernel biodiesel and its blend in a CI engine

The full load performance characteristics of a diesel engine fuelled with palm kernel biodiesel and its blend with diesel fuel are presented in this paper. The biodiesel was synthesised from Nigerian palm kernel oil through a direct base catalysed transesterification process using sodium hydroxide and methanol as the catalyst and alcohol, respectively. The produced biodiesel was blended with neat diesel fuel at a ratio of 20% biodiesel to 80% diesel by volume. The engine torque, brake power, brake specific fuel consumption and brake mean effective pressure were determined for each of the fuels at 400 rpm intervals between 1200 and 3600 rpm. In other to establish a baseline for comparison, the engine was first run on neat diesel. The test results interestingly revealed that the fuel blend (B20) produced higher torque at low and medium engine speeds than neat diesel fuel and unblended biodiesel (B100). This suggests that it can be a suitable fuel for heavy duty engines that are required to develop high torque at low engine speeds. It was also observed that diesel fuel developed higher torque and brake power than the unblended biodiesel (B100) at all tested speeds and showed the least brake specific fuel consumption possibly because of its higher heating value. In all, the palm kernel biodiesel and its blend (B20) exhibited performance characteristic trends very similar to that of diesel fuel thus confirming them as suitable alternative fuels for compression ignition engines.     

A comprehensive study on reduction of NOx emission applying EGR technique in a diesel engine using biodiesel (POME) as fuel with ether-based additives

The energy consumption is increasing rapidly due to population growth, improved living standards and industrialisation. A significant amount of fossil fuels is consumed by the transportation sector, which causes the fast depletion of fossil fuels and environmental pollution. These problems can be overcome by using Biodiesel. This research work aims to reduce the NO_x emission in diesel engines. The literature survey reveals that the use of a fuel additive reduces the emissions by oxygenating the fuel. Among oxygenates, ether proves to behave better than alcohols. Hence, for this present work, two different types of ethers were selected which were not used in earlier occasions. DGME (Diethylene Glycol Monomethyl Ether) and DGMB (Diethylene Glycol Monobutyl Ether) are the two additives selected from the ether group and used as additives with palm oil methyl ester (POME) biodiesel in various proportions and tested in a direct injection compression ignition engine which reduced the emissions. To start with, the engine was run with diesel and subsequently with biodiesel and with the additives. The performance tests were carried out in a single-cylinder, four-stroke, water-cooled engine with and without exhaust gas recirculation (EGR). This engine is coupled with eddy current dynamometer. The use of biodiesel in conventional diesel engines results in substantial reduction in emission of carbon monoxide, particulates and unburned hydrocarbons, but increases NO_x emission. This review focuses on reduction of NO_x emission. Combustion and performance analysis of the engine have also been evaluated.     

Effect of exhaust gas recirculation on a nanoparticle-doped biodiesel- and diesel-blends-fuelled diesel engine

ABSTRACT

This work investigates the effect of adding Cerium oxide nanoparticles at different proportions (30, 60 and 90?ppm) to Calophyllum inophyllum methyl ester and diesel blends (20% CI methyl ester and 80% diesel) in a four-stroke single-cylinder diesel engine. Addition of nanoparticles is a strategy to reduce emission and to improve the performance of the biodiesel. Modified fuels are introduced into the engine by admitting exhaust gas recirculation (EGR) at a rate of 10% and 20% so as to reduce nitrogen oxide (NO_X) emissions from biodiesel and diesel blends. Results revealed a significant reduction in emissions (CO, NO_X, HC and Smoke) at a 10% EGR rate. However, brake thermal efficiency is reduced with an increase in brake-specific fuel consumption at higher EGR rates. Hence, it is observed that 10% EGR rate is an effective method to control the emission of biodiesel and diesel blends without compromising much on engine efficiency.     

Performance and emission characteristics of direct injection diesel engine using linseed oil as biodiesel by varying injection timing

The depletion of fossil fuels and increasing demand leads to research in alternate fuels. The alternate fuels are bio-degradable, renewable and non-toxic. Many types of oils are re-used in biodiesel production, considering their availability, among which linseed oil is the most significant one. Injection timing plays a major role among various injection parameters which affects its performance and emission characteristics. This paper focuses on experimental investigation on a single cylinder, four-stroke direct injection diesel engine with output of 5.2?kW at 1500?rpm at various injection timings, 20, 23, 26 degree BTDC for observing the performance and emission characteristics of direct injection diesel engine using methyl esters of linseed oil and its blends. The blends are B10, B20, and fuel characteristics are observed. The results show that when compared with diesel it gives an increase in BTHE and reduction in SFC. Both the biodiesel blends give lesser NOx. Slightly higher CO and HC emission were found. The performance and emissions were increased in when injection increased.     

Effect of injection pressure on the performance and emission characteristics of CI engine using canola emulsion fuel

Biodiesel is a promising renewable alternative fuel for diesel. The need of biodiesel fuels for the diesel engines is to restrict the dependency on the fossil fuels in context to the world energy oil crisis. The objective of this article is to investigate the performance and emission characteristics of a CI engine with diesel and blends of canola biodiesel Emulsion at 200, 220 and 240?bar. The fuel injection system in a diesel engine is to achieve a high degree of atomisation for better penetration of fuel in order to utilise the full air charge and to promote the evaporation in a very short time and to achieve higher combustion efficiency. Emulsified fuels showed an improvement in brake thermal efficiency of 28.8% at 240?bar accompanied by the drastic reduction in NOx at 200?bar.     

A comparative study of performance and combustion characteristics of a CI diesel engine fuelled with B20 biodiesel blends

This paper aims to study the diesel engine performance and combustion characteristics fuelled with Banalities aegyptiaca oil methyl ester, palm oil methyl ester, sesame methyl ester oil, rapeseed methyl ester oil, soybean oil methyl ester and diesel fuel. In this present work, only 20% of each biodiesel blends was tested in diesel engine; stated that the possible use of biodiesel of up to 20% in a diesel engine without modification in literature. A single-cylinder, auxiliary water-cooled and computer-based variable compression ratio diesel engine was used to evaluate their performance at constant speed and at measured load conditions. The performance and combustion tests are conducted using each of the above test fuels, at a constant speed of 5000?rpm. Thus, the varying physical and chemical properties of test fuels against pure diesel are optimised for better engine performance.

Abbreviations: BP: brake power; BSFC: brake-specific fuel consumption; BTE: brake thermal efficiency; CO: carbon monoxide; CP: cylinder pressure; DP: diesel pressure; EGT: exhaust gas temperature; HC: hydrocarbon; HRR: heat release rate; NO _x : nitric oxides; PM: particulate matter; TDC: top dead centre; VCR: variable compression ratio